"I'll call them back," I told him, when he suddenly picked up my phone and showed me an awesome feature I never knew existed.

Calacanis gave me his phone number and I called him. Instead of ignoring the call, he showed me his screen. It said the normal "Accept" and "Decline" options. But then I noticed two more buttons I had never pushed before: "Remind me later" and "Message."

It turns out if you press "Message," it will send the person a text of your choosing that sounds like you wrote it. The options include: "I'll call you later" and "I'm on my way."

If you go to your text messages, you'll see a text sent at the same time the call was ignored. Meanwhile, your friend will be sent to voicemail. They'll receive your text when they hang up.

A lot of people don't know about the feature, so they'll just assume you texted them promptly. And regardless, it's nicer to send a text immediately, even if you plan to return the call later.

I tried it on my mom and my colleague Steve. Here's what the process looks like: